Leaking shut off valves take very little time to fix. You can literally do this in a matter of seconds. It is unavoidable that these valves will sometimes fail to work since they are used for years and during this time, crud will start to build up on the inside. There are times when there will be no choice but for you to replace the valve. However, you might want to try repairing it first to see if it can be salvaged.
Step 1: Loosen the Valve Screw
Take a pair of slip joint pliers and wrap some masking tape around it. This is necessary if you want to avoid scratching the valve. Locate the packing nut with the pliers. This can be found behind the handle of the valve. Make a 1/8 clockwise turn with it. There are times when this is enough to stop the leak.
Step 2: Turn Off Water Supply
In case the leak continues, you should turn off the house's primary water supply. It is important for you to turn off the water supply because in case a pipe bursts, you could be stuck with water enough to fill a whole bathtub. This can be difficult and messy to deal with. Afterwards, the pipes would have to be drained. It would help you a lot if you have a container close by so that you can catch the leftover water from the valve.
Step 3: Disassemble the Valve
Now it is time to disassemble the shut off valve. You do this by taking off the screw from its handle and untwisting the packing nut. Find the threaded part inside the valve and take this out.
Step 4: Clean the Washers
Check the washers and see if there are any mineral deposits on them. Should this be the problem, take a clean rag and remove the deposits. Be very gentle when doing this so that you do not end up causing more damage.
Step 5: Reassemble the Valve
After cleaning out the washers, you can now re-assemble the valve. When doing this, avoid using materials like pipe dope or plumber's putty. These can lead to added gum on the valve which will make it harder for you to repair it if more leaks occur.
Step 6: Turn Water Supply On
Turn the water line back on to see if there are still any leaks. If you were not able to repair the leak, it is probably time for you to replace the valve altogether. This is also very easy to do and it helps a lot if you take the old one with you to the hardware store so that you have an exact idea of what you will need to get.
Dealing with a leaky shut off valve is easy if you have the proper tools and know-how. This is even something that you can do yourself and it does not require the help of a professional plumber. Remember that the best time for you to replace a leaky valve is when people in the house do not have an immediate need for water. This is so you have some extra time in case you encounter some problems while you are fixing it.